Published 6:30 am, Wednesday, December 15, 2010

Most Houstonians don't spend much time thinking about hurricanes in mid-December as the winter solstice and the shortest day of the year approach. Although next Tuesday marks the first day of winter, solstice also represents a seasonal nadir, when the sun reaches its lowest point in the southern sky and begins its northerly climb toward future summer.

So far this season, the nights have been bracing, but with no hard freeze in the metro area. If urban gardeners have a complaint, it's about the paucity of rain that has left us six inches below normal and flirting with drought.

So why are we thinking about tropical storms at the onset of winter? Two of the earliest forecasts for the storm season that begins June 1 are chilling. They predict another busy season, much like the one just concluded, but indicate the U.S. is unlikely to escape unscathed as it did in 2010, when a seemingly invisible shield shunted the big storms into Mexico, the Caribbean or the North Atlantic.

With the caveat that such early forecasts have a low accuracy rating compared to projections at the beginning of next season, consider that the well-known team of William Gray and Phil Klotzbach of Colorado State University is predicting 17 named storms, nine hurricanes and five intense cyclones. While that's slightly less than this year's 19-12-5 count, the CSU study predicts significantly higher chances of a major hurricane striking the Gulf and East coasts of the United States.

As recounted by Dr. Jeff Masters in his blog on the Weather Underground Web site, the British private forecasting firm Tropical Storm Risk also predicts a busy season, with 15.6 named storms, 8.4 hurricanes and four intense ones. More sobering is their expectation that the U.S. will be hit by five named storms in 2011, including two hurricanes.

The basis for these forecasts is a pool of cool water in the Pacific off South America, known as La Niña, and record high sea temperatures in development zones of the tropical Atlantic, both of which can boost storm formation.

The same weather patterns that protected us this year could ward off whatever comes out of the tropics in 2011. But two years of good fortune might be one too many to expect.